Pin-feed tractor for paper webs

ABSTRACT

THE TRACTOR TYPE OF PIN-FEED DEVICE FOR FEEDING MARGINALLY PREFORATED PAPER WEBS SUCH AS CONTINUOUS BUSINESS FORMS TO, FORM, OR THOROUGH IMPRINTING OR HANDLING MACHINES, PRESENTS PERCULIARLY CONFIGURED ENDLESS BELTS, PINCARRYING ELEMENTS OR CLIPS, AND DRIVE SPROCKETS THEREFOR. THE PIN ELEMENTS ARE DETACHABLE FROM THE ENDLESS BELT AND ARE PREFERABLY MADE OF PLASTIC ALTHOUGH FOR SOME PURPOSES METAL MAY BE USED. A SERIES OF TRANSVERSE RIBS ARE PRO-   VIDED ALONG THE BELT, ALTERNATE ONES OF WHICH ARE SPACED FOR INTERLOCKING ENGAGEMENT WITH TRANSVERSE NOTCHES OR RECESSES FORMED ON THE RESPECTIVE PIN ELEMENTS. SUBSTANTIALLY COINCIDENTALLY WITH THESE NOTCHES, THE PIN ELEMENTS ARE THEMSELVES PROVIDED WITH DOWNWARDLY PROJECTING TRANSVERSELY DISPOSED RIB PORTIONS OF PROTUBERANCES.

R. w. BREWSTER ETAL 3,606,122" PIN-FEED TRACTOR FOR PAPER WEB:

* Sept. '0; 1911 -2 Sheets-Sheet 1 Filed April 17, 1969 dull-W wit/M, 4 ATTORNEYS Sept. 20, 1971 R. w. BREWSTER EI'AL 3,606,122

PIN-FEED TRACTOR FOR PAPER WEBS Filed April 17, 1969 2 Sheets-Sheet 2 in j l I 15 I ||1 i as C Q! a? 35 34' INVENTORS,

Aamm A! flzewsme lFm MoA/a .6 (a/wee ATTORNEYS United States Patent 3,606,122 PIN-FEED TRACTOR FOR PAPER WEBS Ronald W. Brewster, Villa Park, Ill., and Raymond E.

Connor, Durham, N.H., assignors to Moore Business Forms, Inc., Niagara Falls, N.Y.

Filed Apr. 17, 1969, Ser. No. 817,022 Int. Cl. B65h 17/38 U.S. Cl. 226-74 6 Claims ABSTRACT OF THE DISCLOSURE The tractor type of pin-feed device for feeding marginally perforated paper webs such as continuous business forms to, from, or through imprinting or handling machines, presents perculiarly configured endless belts, pincarrying elements or clips, and drive sprockets therefor. The pin elements are detachable from the endless belt and are preferably made of plastic although for some purposes metal may be used. A series of transverse ribs are provided along the belt, alternate ones of which are spaced for interlocking engagement with transverse notches or recesses formed on the respective pin elements. Substantially coincidentally with these notches, the pin elements are themselves provided with downwardly projecting transversely disposed rib portions or protuberences.

Outward portions of these successive clips or pin-carry ing elements abut each other but inwardly disposed parts are narrowed, both to prevent jamming when the clips move in their circular path about the drive sprockets, and to clear the intervening alternate ribs on the belt.

The peripheries of the prockets are provided with two series of transverse grooves or notches between the teeth thereon, those of one series alternating with those of the other around the sprocket; one series contoured to accommodate in driving relationship the ribs of the belt and the other to receive and accommodate the ribs or projecting portions of the pin-carrying elements and maintain the flexure and path of the belt at the ends of the device truly arcuate.

The feed pins themselves are carried by lateral extensions from the body portions of the clips or pin-carrying elements, and the pins project well beyond the level of the plane of the web being fed, and a hinged web guide is disposed above the plane of the web with a longitudinal groove to receive the outer ends of the pins during operation.

This invention relates to web-feeding devices for moving marginally perforated webs of paper, such as continuous business forms, to, from, or through business machines or other treating or handling apparatus.

The invention has for its general object the provision of several structural improvements in an endless belt or tractor type of web-feeding device, which involves the provision of pin-carrying elements which are detachable from the driving belt while at the same time preserving the stability of the feeding assembly and the accuracy of the positioning of the pins and therefore corresponding accuracy in the feeding of the Web.

The invention in its preferred embodiments contemplates the provision of driving sprocket wheels which are provided with means on their peripheries constructed and arranged to operatively engage with the endless belt and to accommodate the clip or pin-bearing elements carried thereby.

Enabling features directed to this object comprise: the provision of a series of projections on the belt, alternate ones of which are spaced to engage corresponding portions of the successive clips, and the intervening ones to remain clear during straightaway travel of the belt; the sides of successive adjacent clips designed to abut each other during travel at their outer portions but constricted at their inward portions to both avoid jamming when going around the circular periphery of the sprocket wheels and to leave the intervening belt carried projections clear as indicated. The inward portions of each of the respective clips are shaped to provide a transverse projection substantially coincidental with the alternate belt projections which the clip engages.

Further features of novelty comprise the provision of driving sprocket wheels which are peripherally provided with a series of teeth, the spaces between certain of the teeth adapted to provide a driving connection with the alternate projections on the belt, and the spaces between alternate pairs of teeth being shaped to receive the projections on the successive clips.

Other objects and features of novelty will be apparent from the following specification when read in connection with the accompanying drawings in which one embodiment of the invention is illustrated by Way of example.

In the drawings:

FIG. 1 is a somewhat schematic view of a paper-feeding pin tractor embodying the features of the invention;

FIG. 2 is a view in side elevation of the novel feed belt and sprocket assembly;

FIG. 3 is a top plan view of the assembly of FIG. 2 as seen from the line 3-3 of FIG. 2;

FIG. 4 is a fragmentary view in vertical section taken on line 44 of FIG. 3;

FIG. 5 is a view in perspective of one of the pincarrying elements or clips; and

FIG. 6 is a fragmentary view in elevation on an enlarged scale showing the interfitting of the sprocket and clips.

A tractor device embodying the principles of invention is indicated at 10 in FIG. 1 of the drawings and comprises a body or frame portion including the rearward part 11 and a forwardly projecting frame part 12. A properly configured plate 15 comprises a ledge providing a lower web guide along which the margin of the perforated paper web moves. An upper guide member 16 is hinged (the hinge not shown) to a portion of the body 11 so as to swing to and from a position suggested in FIG. 1 where an attached grooved or channelled portion 17 embraces the upward ends of the feed pins on the tractor.

Rotatably carried by the body frame 11, 12 are the sprocket wheels 20 and 21, either of which may be the driving sprocket, although in this instance the wheel 20 being provided with an internally splined disk 23 may be considered the driving element and sprocket wheel 21 the idler or follower member, the latter wheel being carried by any suitable type of shaft 24 mounted in bearings in the frame. Trained about the sprocket wheels 20 and 21 is the endless belt 25, as best distinguished in FIGS. 3, 4 and 5 of the drawings. The belt is made of flexible material but material which is not subject to any significant elongation. Reinforced rubber or plastic may be found suitable. At intervals along the inward side of the belt 25 there are provided transverse ribs or projections 26 which serve the purpose of providing cooperating driving means for the belt and also means for attaching pin-carrying clips thereto.

The pin-carrying elements or clips secured successively along the endless belt 25 are given the general designation 30 and are best seen in FIGS. 1 and of the drawings. Each of these pin-carrying elements is provided with oppositely facing vertically arranged platelike structures or walls 31 and 32 between which extends a bridging portion 33. The wall portion 32 is provided with an extension or arm 34 upon which is mounted the feed pin 35, this pin being of a height to extend beyond the lower web guiding ledge 15, through the web and up into the grooving guide member 17.

The bridging or connecting portion 33 of the clip is provided with a pocket, recess, or trough 37 which is adapted to receive one of the ribs 26 of the belt 25, the lower portion 38 of the bridging element 33 providing an inwardly extending projection.

The upper portions of the wall members 31 and 32 are provided with inwardly directed spur elements 39 which embrace the margins of the driving belt 25, the belt being sufliciently flexible to be snapped beneath the spurs and into the interlocking engagement between ribs 26 and the trough or pocket 37.

As most clearly depicted in FIG. 4 of the drawings, the engagement of each of the pin-carrying elements or clips 30 with the belt is with alternate ribs 26 of the belt, the intervening ribs during the passage of the clips along the straightaway portions of the run being in the clear. It will also be noted that the contour of the clips narrows toward the inward portions so that only the uppermost portions of the side wall structures 31 and 32 are in abutment.

Each of the sprocket wheels 20 and 21 are provided with a novel tooth structure. This construction involves the provision of spaced pairs of teeth 40, a relatively shallow notch or groove 41 being provided between the teeth of each pair. Between the pairs of teeth there is provided a somewhat deeper notch or pocket 42. The notches 41 are spaced apart a distance equal to the distance between alternate ribs 26 on the belt and as the belt proceeds around the sprocket wheel alternate notches 26 are received in driving relationship within the notches 41 between the teeth and power is transmitted to the belt itself. It will be recalled that each of the clips 30 straddles the intervening ribs 26 and provides a transverse projec tion 38 coincidental with said intervening ribs. These projections are of a generally arcuate profile and are adapted to be received within the larger grooves or notches 42 formed in the periphery of the sprocket.

In FIG. 6 of the drawings it will be observed that the interfitting of the clip projection 38 within the groove or notch 42 is not a close or rigid one, but one in which the contact between the surfaces of these two portions is substantially tangential as at 3812, with the side walls of the projection 38 and the groove 42 spaced slightly apart as at 42a. Also the profiles of the surfaces of parts 38 and 43 need not be strictly circular arcs but more of an ovate configuration.

The above provisions are to maintain the neutral axis of the belt as it passes around the sprocket to preserve an arcuate rather than a chordal posture.

The arcuate paths of surfaces 38a and 40 are coincident as rotated about the axes of sprockets 20 and 21 in order to ensure that the neutral axis of the belt operates in a circular are.

It will be seen that the present invention provides an eificient, accurate, and durable tractor feed device for paper webs and one which not only affords a positive drive but also provides means for replacement of individual pincarrying elements or clips as many be necessary.

Various changes and modifications may be made in the embodiment of the invention illustrated and described 4 herein without departing from the scope of the invention as defined by the following claims.

We claim:

1. A pin-type web-feeding tractor device comprising a supporting frame, belt guiding wheels rotatably mounted in bearings on said frames, at least one of said wheels being a driving sprocket wheel, a flexible endless belt trained about said wheels for movement therewith, and a series of detachable pin-carrying elements clipped onto said belt, and at least one web-feed pin carried by and projecting from each of said elements to engage a feedhole in the web being fed, the belt being provided with spaced projections therealong and the said elements being provided with portions interlocking with alternate ones of said projections, and the sprocket wheel having portions on the periphery for driving engagement with the intervening ones of said belt projections, the successive elements having at least their inward portions spaced apart to clear said intervening projections for engagement by said sprocket wheel, each element being approximately trapezoidal in longitudinal profile and the outward portions of adjacent elements being in abutment at least during straightaway travel, and the inward portions being narrowed and spaced apart to clear certain intervening belt projections and to prevent jamming when going around said wheels.

2. A pin-type web-feeding tractor device comprising a supporting frame, belt guiding wheels rotatably mounted in bearings on said frames, at least one of said wheels being a driving sprocket wheel, a flexible endless belt trained about said wheels for movement therewith, and a series of detachable pin-carrying elements clipped onto said belt, and at least one web-feed pin carried by and projecting from each of said elements to engage a feedhole in the web being fed, means being provided on said sprocket wheel for driving engagement with said belt, and means being provided on said sprocket wheel for the accommodation of said elements, a series of spaced projections being provided along said belt, alternate ones of which are for such driving engagement with said sprocket wheel, and means being provided on said elements for interlocking engagement with the intervening ones of said ibelt projections. k

3. The device as set forth in claim 2, in which the said means on said elements comprise portions having grooves in their outward surfaces for the interlocking reception of belt projections, and projections on their inward portions coinciding with said grooves and constituting means for engagement by the corresponding means on said sprocket wheel to maintain the proper neutral axis posture of the belt and clips in their passage around said sprocket.

4. The device as set forth in claim 3, in which said sprocket wheel is provided with a peripheral series of teeth, certain spaces between the adjacent teeth receiving the alternate belt projections, and alternate spaces between teeth receiving the projections from the pincarrying elements.

5. A pin-type web-feeding tractor device comprising a supporting frame, belt guiding wheels rotatably mounted in bearings on said frames, at least one of said wheels being a driving sprocket wheel, a flexible endless belt trained about said wheels for movement therewith, and a series of detachable pin-carrying elements clipped onto said belt, and at least one web-feed pin carried by and projecting from each of said elements to engage a feedhole in the web being fed, means being provided on said sprocket wheel for driving engagement with said belt, and means being provided on said sprocket wheel for the accommodation of said elements, the interconnection of said sprocket wheel and said elements comprising transverse grooves in the periphery of said wheel and transversely extending inward projections on each of said elements, the profiles of the confronting surfaces of said grooves and projections being generally arcuate, but

actual contact being limited to a substantially tangential contact at the central portions of said generally arcuate surfaces.

6. A pin-type web-feeding tractor device comprising a supporting frame, belt guiding wheels rotatably mounted in bearings on said frames, at least one of said wheels being a driving sprocket wheel, a flexible endless belt trained about said wheels for movement therewith, and a series of detachable pin-carrying elements clipped onto said belt, and at least one web-feed pin carried by and projecting from each of said elements to engage a feedhole in the web being fed, the belt being provided with equally spaced projections therealong and each of said elements is provided with a portion interlocking with one of said projections, each element being approximately in abutment with each other with the inward portions References Cited UNITED STATES PATENTS 1/1963 Castleton 226-74 4/1970 Hepp et al. 226-74 OTHER REFERENCES Hubson, V. L.: IBM Technical Disclosure Bulletin, vol. 1, No. 4, December 1958.

ALLEN N. KNOWLES, "Primary Examiner 

